Imaging The Spaghetti Nebula

[Mikey0368]

I got 47 x 240s at the Spaghetti Nebula earlier in the week but the results are very faint. I know it's a faint target but I was hoping for better!

I'm using a ZWO ASI294MC Pro and SW Esprit 100ED. Do I just need more time on it, or longer exposures, or higher Gain (currently 120)?  Any tips would be appreciated.

Thanks.

[PeterCPC]

I have never imaged it but I would think that you need longer exposures and lots of them.

[ONIKKINEN]

Increasing gain will not be bringing fainter stuff in, it will just make brighter stars saturate faster and make the image look brighter. Higher gain has a lower read noise but with exposures as long as yours it really doesn't matter any more with modern CMOS cameras. I personally wouldnt take longer exposures than the ones you are already taking as it increases the chances of losing more data due to wind/mechanical issues etc. Your camera is pretty good so longer than 60s exposures are pretty much guaranteed to be sky-limited unless shooting narrowband, hence almost no benefits from longer subs.

You did not mention using a filter (H-alpha/O3/both) with your setup, but using a narrowband filter would make the image be better much faster. Many such filters out there for colour cameras like the Optolong L-extreme. Also, the kind of sky conditions (light pollution, etc) you image from will dramatically increase or decrease the time required to reach a good looking result in the end. But could also just be not quite enough integration.

But in the end its difficult to say without seeing the picture first, mind posting what you are working with now as it is?

[The Lazy Astronomer]

51 minutes ago, Mikey0368 said:

I got 47 x 240s at the Spaghetti Nebula earlier in the week but the results are very faint. I know it's a faint target but I was hoping for better!

I'm using a ZWO ASI294MC Pro and SW Esprit 100ED. Do I just need more time on it, or longer exposures, or higher Gain (currently 120)?  Any tips would be appreciated.

Thanks.

The spaghetti nebula is very faint, and also HUGE. I was playing around a few months back and I think I had to shoot a 6 panel mosaic to get most of it - 9 panels would frame it nicely (with almost the same equipment as you: esprit 100 & 294MM). I think l deleted the data because it was poor (lots of passing and high cloud), but I'll see if it's still sitting in the recycle bin to show you an example when l get back from work. 

You also don't mention the use of any filters, this target really benefits narrowband imaging, Ha particularly.

Edited January 7, 2022 by The Lazy Astronomer

[iantaylor2uk]

I think if you use a filter such as the L-Enhance or L-Extreme, then there is a case for using higher gain on the CMOS cameras. On my ZWO 071 MC Pro camera, I have played with gain quite a bit, and although I have used unity gain (90 on this camera) I have found better results at higher gain (such as 200). The noise is also lower at higher gain. There have been others on this forum (and Cloudy Nights) who have also used high gain values successfully on this camera. If I'm just using a UV/IR filter, the higher gain means I can go to shorter exposures, but with the L-Enhance or L-Extreme filters, you can keep the longer exposures and it should also bring out some of the fainter details. I typically use 120 sec exposures for most DSO's when using the L-Enhance filter, and this works quite well - I'll have to try it out on the Spaghetti Nebula 

Edited January 7, 2022 by iantaylor2uk
Typo

[Mikey0368]

Cheers folks. I should have mentioned the filter right enough!  It's an IDAS LPS-D3 that I'm using.

From the answers above I suspect I just need to add more data. It's to be clear for a while this evening again so I'll hopefully get a few more hours.

[Mikey0368]

It might also be worth adding that I used APP to stack the flats and calibration frames and then StarTools to process it. A friend has tried processing the .fits file in Pixinsight this morning and hasn't had much luck either.

[The Lazy Astronomer]

Are you doing a mosaic, or were you imaging a particular area of it?

[Mikey0368]

Not a mosaic,  just wherever NINA decided where it would be when centred.

[Phillyo]

I would add more data. Increasing exposure length will just increase light pollution collection. Increasing gain will lower the full well depth and noise but not give you anything you want. Just get more and more 4min subs. It is a VERY faint object!

[Mikey0368]

Thanks all. I think I'll just keep adding to it with 240s exposures at Gain 120 and will hopefully get 3 or 4 hours tonight.

Its size is about 3 degrees across, similar to Andromeda which just fits into my FoV, so I'm assuming I'll get all of it in one frame and not need to do a mosaic. Astronomy.tools isn't being very helpful with this one..........

[scotty38]

That seems an odd view as NINA has it down as 3.3 degrees object. Using Astronomy Tools it shows it fitting my fov with a WO GT81 with 0.8x flattener and the same camera yet the FOV of my setup is 2.87x1.96. The NINA view suggests I'd need at least a 2x2 Mosaic so not sure why Astronomy tools shows it fitting in one frame....

[geeklee]

@Mikey0368 Here's a view from Telescopius simulator.

550mm FL, ASI294MC Pro camera size.  Camera angle 0deg.

Single pane, centred:

3x3 Mosaic:

I'm currently imaging with a 135mm lens but a smaller ASI183MM and it just fits.

Edited January 7, 2022 by geeklee

[The Lazy Astronomer]

1 hour ago, geeklee said:

@Mikey0368 Here's a view from Telescopius simulator.

550mm FL, ASI294MC Pro camera size.  Camera angle 0deg.

Single pane, centred:

3x3 Mosaic:

I'm currently imaging with a 135mm lens but a smaller ASI183MM and it just fits.

 

2 hours ago, Mikey0368 said:

Thanks all. I think I'll just keep adding to it with 240s exposures at Gain 120 and will hopefully get 3 or 4 hours tonight.

Its size is about 3 degrees across, similar to Andromeda which just fits into my FoV, so I'm assuming I'll get all of it in one frame and not need to do a mosaic. Astronomy.tools isn't being very helpful with this one..........

Like I said, it is huge!! With the same scope and same sensor size, I got almost all of it in a 3x2 mosaic, but 3x3 does frame it better.